Slide valve for regulating the flow of solids



Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE SLIDE VALVE FOR REGULATIN G THE FLOW OF SOLIDS of Delaware Application April 3, 1950, Serial No. 153,677

1 Claim.

The present invention is directed to an improved slide valve for controlling the flow of nely divided solids. In its more particular aspects, the invention is directed to apparatus for controlling the iiow of a suspension of finely divided solids in a iiuidized condition.

In the petroleum industry, and particularly in catalytic cracking of hydrocarbons when employing the iluidized solids technique, it is necessary to move large quantities of finely divided catalyst of a particle size from to 200 microns. In moving the iinely divided powdered catalyst, it is usually agitated with air or other vaporous medium and suspended therein so that it behaves much like a fluid.

It has been customary in the past to use slide valves in which a slide may move past an orifice and thus regulate the flow of solids moving therethrough. The impngement of the particles on the metallic surfaces o1 the orice and on the slide restricting the orii'lce has been such to cause the orice and the slide to be eroded away to the extent that within a short period of operating time the slide and the oriiice itself become deteriorated to the extent that the valve is inoperable and control of flow is lost.

The problem is not restricted to catalytic cracking but may be encountered in operations in which suspensions of nely divided solids are caused to flow past a restricted area.

The slide valves presently used on fluid catalytic units to control the flow of catalyst into and out of the various vessels and lines consist of a renewable slide which operates against a single seat. The flow of catalyst through the valve is regulated by the position of the slide in relation to an opening in the seat. The slide is moved through its travel limits by a hydraulic cylinder located on the bonnet of the valve. When a new valve` is installed in a line and the hydraulic cylinder adjusted to set the slide to provide an area of iiow through the valve oi a given number of square inches, it will allow a certain number of pounds of catalyst to pass through the valve in a given unit of time. However, as the slide and the seat become worn due to the constant impingement of solid particles against them the open area becomes greater in number of square inches than originally and the amount of catalyst which passes through this larger area per unit of time accordingly becomes greater than that originally contemplated. To regulate the now of catalyst through the valve at substantially the original rate, it is customary to advance the original slide by means of the hydraulic cylinder to reduce the area of now to approximately the original area. However, this is impractical because the single slide and the orifice which are exposed to the impingement of abrasive particles become worn to the extent that the valve is merely an obstruction of flow in the line with no control at all.

It is the main object of the present invention to provide an improved valve which is resistant to ravages of erosion by virtue of its construction and operation.

Another object is to provide a valve which allows positive control of flow of nely divided solids.

A still further object is to provide a valve with a plurality of adjustable orifices exposing a minimum area of metal to erosion.

The present invention provides an improved slide valve which includes a valve body defining an inlet and an outlet. Located intermediate the inlet and the outlet is an oriice plate defiining at least one orifice through which the finely divided solid passes from the inlet to the outlet of the valve body. Arranged in juxtaposition to the orifice plate and sliding thereunder are two slides which are designed to move in relation to each other to define with the orifice in the orifice plate a plurality of adjustable orifices. The slides are connected to stems, which protrude through the valve body into bonnets, and are attached to hydraulic cylinders located on the outside of the bonnets for control of the slide.

The invention will be further illustrated by reference to the drawing in which:

Fig. 1 is a view looking down on a valve in accordance with the present invention embodying two slides;

Fig. 2 is a cross-sectional view of the device of the present invention taken along lines II-II of Fig. l;

Fig. 3 is a similar view to Fig. l with parts omitted showing a different arrangement of the diagonal slot of Fig. l; and

Fig. 4 is a similar View to that of Figs. 1 and 3 showing a further arrangement of the oriiice plate of Figs. 1 and 3.

In the several figures of the drawing identical numerals will be employed to designate identical parts.

Referring now to the drawing, numeral II de- `lines a valve body including an inlet I2 and an outlet I3. Arranged intermediate the inlet and outlet is a valve seat I4 dening an orifice I5. In juxtaposition to seat I4 and slidable thereunder are two slides I6 to which are att-ached stems I'I which protrude through valve body il into bonnets I8 and which are connected to hydraulic cylinders I9 for introduction of hydraulic fluid thereto. Valve body Il may be attached to suitable conduits, not shown, by bolting flanges thereto thus allowing a luidized suspension of solids passing through such conduits to be controlled by the valve of the present invention.

The embodiment of Fig. 3 is similar to that of Figs. l and 2 with the difference that orice plate I4 has been replaced with a modiiied orifice plate in which are located diagonal slots 26 which are arranged so that the same portion of slides I6 will not be exposed to contact with particles flowing through the slots 26.

The embodiment of Fig. 4 is diierent from that of Figs. 1 to 3 to the extent that orice plate 29 denes slots which are in staggered relationship to each other and may be of different sizes to define diferent areas of flow. It will be seen lfrom Figs. 1, 2, 3 and 4 that the same portions of slides I0 are not employed to control the ow through the several orifices.

In employing the device of the present invention as illustrated by the several embodiments of the drawing, the two slides I6 may be operated to move in unison to denne an area of fiow, with the orices in the orice plates i4, 25 and 22, to give the desired rate ci now through the oriiices in the several respective oriiice pates mentioned. As the two slides i5 andthe orifice plates become worn only in the area where catalyst has Iiowed therethrough, the slides are then moved across the slots together maintaining a predetermined distance between the slides to give the desired area of 110W so that new, unworn metal or" both the slides and the orifice plates is exposed to the erosive action of the catalyst.

It is important in the practice of the present invention that the two slides move together across a given orifice so that the only part of the slide exposed is that part defining the adjustable orice and the only part of the oriiice plate that is exposed to the erosive action of the solid particles is that part which is not covered by the slide. In short, by providing a valve in accordance with the present invention with two slides moving in relationship to each other it is possible to reduce the amount o F erosion, to control the flow of finely divided particles and maintain the desired rate of ow at all times. A valve in accordance with the present invention may allow a slide valve to have double the life of the conventional slide valve of the prior art.

Although the orifice and the orii'lce `plates have been shown to be roughly rectangular in shape, it is possible to have these oriiices of any size or shape provided they are located in the orice plate so that diiierent portions of the slides are exposed to the iiow of solids through the particular orifice. 1n short, the oriiices in the orice plates may be rectangular, circular, triangular or any desired shape as long as the foregoing provision is met.

While the present invention has shown the slide stems being actuated hydraulically, other power means may be substituted therefor. The valve stems may be operated by electric motors, air motors and the like. It is preferred, however, to use a hydraulic cylinder.

From the foregoing description and the description taken with the drawing, it is apparent that the present invention provides an improved valve in which, during the operation of the valve, a plurality of new orices or apertures thereof, through which the catalyst passes, are presented continuously and, by moving the slides in relationship to each other across a single orirlce or a plurality of orifices, it is possible to expose fresh, uneroded surfaces to allow control of iiow of solids. From a single or a Iplurality of orices in an orifice plate of a slide valve of the present invention, it is possible to dei-lne with the two slides a plurality of other orifices 4for control of catalyst iiow.

While the apparatus of the present invention has been described with respect to the two slides moving in unison, it will be apparent that the same desirable eiiects may be obtained by moving one slide to a lirst position and then controlling flow by moving the other slide' in relation to the slide in its rst position. Thereafter, the slide in the iirst position may be moved to additional positions to expose fresh surfaces of the slide and to allow full control of the operation.

The nature and objects of the present invention having been completely described and illustrated, what 1 wish to claim as new and useful and to secure by Letters Patent is:

A slide valve adapted for controlling the flow of iiuidized solids which comprises, in combination, a valve body having a central passage connected by an inlet and an outlet, a pair of slides mounted en the valve body arranged to move in a plane perpendicular to the axis of the central passage and the valve with the adjacent edges of the pair of slides the leading edges and parallel t0 each other, an orifice plate mounted in the valve body between the inlet and outlet and in juxtaposition with said slides and parallel thereto, the iiow opening of the orifice plate having at least two parallel boundaries which make an acute angle with the parallel leading edges of said pair of slides whereby the maintenance of a xed distance between said leading edges while moving them along their plane of movement from one position to another sequentially changes the portion of said leading edges and the portion of the boundary of said opening in the oriice plate which form the now opening through the central passage of the valve.

CHARLES W. LUBBOCK.

References Cited in the le of this patent IUNITED STATES PATENTS Number Name Date 132,974 Miles Nov. 12, 1872 143,045 Weaver Sept. 23, 1873 412,789 Probert Oct. 15, 1889 824,585 Rieth June 26, 1906 953,133 Frink Mar. 29, 1910 993,400 Ruth July 18, 1911 1,550,725 Jung Aug. 25, 1925 1,838,656 Bullock Dec. 29, 1931 2,079,743 Krieger May 11, 1937 2,194,254 King Mar. 19, 1940 FOREIGN PATENTS Number Country Date 664,505 Germany of 1935 

